Release 3.22.5 (2026-09-17)

• Based on upstream Nix 2.35.2.

Performance improvements

• libutil/serialise: Use zero-copy copy_file_range for copying PosixFileSourceAccessor -> FdSink by @xokdvium in DeterminateSystems/nix-src#630

Full Changelog: v3.22.4…v3.22.5